Study On Forming Process Of Metal Powder Additive/Subtractive Manufacturing

Additive and subtractive hybrid manufacturing technology is a new technology that integrates CNC machining with additive manufacturing.It not only has the advantages of simple process,low cost and easy processing of complex shape parts in additive manufacturing,but also has the advantages of high processing accuracy and good surface finish in subtractive manufacturing.Thus it will guarantee a broad application prospect.This paper will go into the research of forming processing of the hybrid manufacturing parts of the additive and subtractive manufacturing based on the laser cladding coaxial powder feeding.The details are as follows:(1)Simulation of ABAQUS temperature field is completed.The Temperature Variation of Laser Cladding of single layer and single layer cladding layer are investigated.And optimizing the weld pool size by changing the laser power and scan rate of different cladding layers is used to obtain better cladding quality.(2)Researches on the influence factors of quality of single-channel single-layer cladding quality based on laser co-axial powder feeding manufacturing technology are taken.Single factor and orthogonal experiments are carried out successively.The effects of the main process parameters,such as powder feeding rate,laser power and scanning speed,on the height,width,depth,shape coefficient and dilution rate of the cladding layer are investigated by single factor experiment and the microstructure of the cross section of the cladding layer is observed by an ultra depth of field microscope.Orthogonal tests are performed based on the results of single factor experiments to determine the appropriate range of process parameters.The orthogonal test results are analyzed by the range method and the variance method,and the optimal process parameter matching control strategy is obtained.The width and height of cladding layer are analyzed and they are validated.(3)Investigations are taken to study the mechanical properties of the formed thin-wall specimens which are based on the additive and subtractive hybrid manufacturing technology.After the 80-layer single-layer cladding is applied,the thin-walled specimens are obtained by milling in subtractive manufacturing on both sides,when the temperature is 250±50℃.The orthogonal experiments are used to investigate the effects of different processing parameters such as powder feeding rate,laser power and scanning speed on the residual stress and tensile properties of the thin-walled specimens.Based on the least square method,the tensile properties such as tensile strength,yield strength and elongation are analyzed.The tensile performances are optimized by using MATLAB genetic algorithm for single and multiple targets,and the reasonable technological parameters war obtained.Then they are validated.(4)Through the annealing heat treatment test,the effects of different heat treatment temperatures on the microstructure,tensile properties,fracture morphology and residual stress of thin-walled specimens are investigated,and the optimal heat treatment process is obtained.